Swinging gate for jet boat



Em. 1, 1963 w. c. CHRISTENSEN 3,070,956

I SWINGING GATE FOR JET BOAT Filed March 2, 1961 2 Sheets-Sheet 1 llt I"HUI III- INVENTOR. WARREN C. CHmsTENsEN Y 3%; WM 5M1 mm" Jan. 1, 1963w. c. CHRISTENSEN 3,070,956

SWINGING GATE FOR JET BOAT Filed March 2, 1961 2 Sheets-Sheet 2 l l IIII 3 I II I l IIIIIIIIIIIIIIII'll!I'I'IIIIII'IIII'IIIIIIIA WARREN C.CHmsTENsEN fzhmffi/M Mmza/d Afforneys United States Patent 3,070,956SWINGING GATE FOR JET BOAT Warren C. Christensen, Indianapolis, Ind.,assignor to The Buehler Corporation, Indianapolis, Ind., a corporationof Indiana Filed Mar. 2, 1961, Ser. No. 92,968 4 Claims. (Cl. 6035.54)

The present invention relates to jet propelled watercraft and moreparticularly to means for controlling the direction of such craft.

At least one form of water jet-propelled boat involves an enginearranged to drive a pump which is located within a conduit through theboat. Water is drawn into the conduit through an intake opening at thebottom of the hoat, is pumped through the conduit by the pump and isexhausted in a stream from the rear of the boat, the stream leaving theboat above the Water within which the boat is floating or is supported.The propulsion principle depends directly on a basic law of physicswhich prov des that every action has an equal and opposite reaction.Thus, as water is ejected astern, the boat moves forward.

One problem present in the construction and operation of such waterjet-propelled boats is that of controlling the direction of movement ofthe boat whereby the boat moves forwardly, rearwardly or retainsposition. This control may be accomplished by deflecting the stream ofwater as it leaves the rear of the boat in such a manner as to cause thestream to flow forwardly of and beneath the boat. There are presentlyavailable slidable devices for accomplishing such deflection; however,such devices offer a relatively great frictional resistance to movementwhen they are operated in the jet stream. Therefore, a primary object ofthe present invention is to provide means for controlling the directionof a jet boat whereby relatively easy shifting from one operatingposition to another is permitted.

A further object of the present invention is to provide a jet boatdirection control which may be easily shifted from one operatingposition to another even though the jet pump is operating at relativelygreat speed.

Still another object of the present invention is to provide a jet boatdirection control which provides greater clearance for sand to be washedthrough the control than does presently available direction controlapparatus of this type.

Further objects of the present invention are to provide a jet boatdirection control which is easier to operate, which lends itself tobetter styling, and which lends itself to easier mechanical couplingthan presently available direction control apparatus of this type.

Related objects and advantages will become apparent as the descriptionproceeds.

' One embodiment of the invention comprises a direction control systemfor a water-craft including means for moviilg water in a jet rearwardlyof the craft and a gate pivotally mounted on the craft for controllingthe flow of: the jet. The gate is provided with an aperture therethroughwhich may be positioned in registry with the jet to permit continuedrearward flow thereof. The gate is also provided with a solid portionwhich may be positioned to block flow of the jet. The gate is furtherprovided with a concave portion which may be positioned to redirect thejet forwardly of the craft.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims.

FIG. 1 is a side elevation of a jet boat incorporating the noveldirection control of the present invention.

FIG. 2 is an enlarged vertical longitudinal section of the rear of theboat of FIG. 1 taken along the line 2-2 of FIG. 3 in the direction ofthe arrows.

FIG. 3 is a horizontal section taken along the line 3-3 of FIG. 2 in thedirection of the arrows.

FIG. 4 is a vertical section taken along the line 44 of FIG. 3 in thedirection of the arrows.

Referring now more particularly to the drawings, there is illustrated ajet boat 10 having a hull 11, the hull being provided with an intakeopening 12 communicating between the bottom of the boat and a pump 13.The pump 13 has a passage therethrough communicating between the intakeopening 12 and a passage 15 through a tailpipe 16 secured to the rear ofthe boat. The pump 13 is driven by a conventional marine engine 14through shaft 14A and functions to pump water from the intake 12 to andout of the rear of the boat. The water is formed into a stream by theconverging surface 17 of an annular member 18 fixed within the passage15 and passes through an adapter 19 secured to the tailpipe 16 andforming a part of the tailpipe assembly, the adapter being provided withan aperture in registry with and the same size as the exit end ofannular member 18. When the boat is moving forwardly, the stream isprojected through the adapter leaving the boat above the water line.

Fixed to the transom 20 of the craft is a housing 21, one function ofwhich is to conceal the direction control of the present invention. Itshould be noted that the housing 21 has an aesthetically pleasingsemi-cylindrical shape which is permitted by the corresponding shape ofthe direction control. The housing 21 also functions as a mount for apair of deflectors 22 which are pivoted upon rearwardly projectingelements 25 and 26 integral with the housing. Any suitable means may beused to pivot the deflectors one way or another to deflect therearwardly moving jet stream in a horizontal direction for steering theboat. Since the deflectors 22 do not form a part of the presentinvention, they will not be described in further detail.

Pivoted upon the tailpipe 16 about an axis 27 is an arcuately shapedgate 39 including a part-cylindrical portion 31 (which extends throughapproximately degrees) and radially extending arms 32 which connect thepartcylindrical portion 31 with the bearings 35 also forming a part ofthe gate and providing the pivotal mounting for the gate. The gate maybe pivoted about its axis by any suitable means such as, for example,cables 36 which are connected to the edges of the part-cylindricalportion and extend through the transom into the boat for operation bysuitable steering means.

The part-cylindrical portion of the gate has formed at horizontallyspaced locations therealong, various control surfaces which are adaptedto control in one manner or another the stream of water being projectedfrom the tailpipe assembly. At the leftward portion of the gate, asviewed in FIG. 4, there is provided a circular aperture 37 which has asize equal to the passage through the adapter 19. The aperture 37 is sopositioned vertically that the gate may be pivoted to a position whereinthe aperture is in registry with the exit end of the passage through thetailpipe assembly and the water being pumped into the tailpipe will beprojected directly rearwardly for moving the boat in a forwarddirection. As has been mentioned, the deflectors 22 may be used todeflect the stream passing through the aperture 37 in order to steer theboat in one direction or another.

It should be noted that the exit end 40 of the adapter has apart-cylindrical configuration which is just adjacent to and isconcentric with the part-cylindrical portion 31 of the gate 30. For thisreason, the part-cylindrical portion 31 will remain adjacent to the exitend of the tailpipe even though it is pivoted by the cables 36. Thecentral section 41 of the part-cylindrical portion 31 may be positionedas illustrated in FIGS. 3 and 4 directly covering the exit end of thetailpipe 16. In this position, the passage of water from the tailpipe isblocked and the water is bottled up preventing any thrust being producedto move the craft through the water.

The part-cylindrical portion 31 has formed therein at its rightward endas viewed in FIG. 3 a scoop-shaped or concave section 42. The section 42is so proportioned and arranged within the gate that the gate may bepivoted to a position wherein the upward end portion of the scoop ispositioned directly rearwardly of the tailpipe exit. The scoop 42extends downwardly a substantial distance and does not curve forwardlyagain until it is below the housing 21 (FIG. 2) and an angularlyarranged guide 45 secured to the transom 20 and the lower surface of thehousing 21. It should be mentioned that the adapter 19 extendsdownwardly to engagement with the lower portion of the housing and issufficiently wide so as to form, with the section 42, a closed conduitwhich opens forwardly at the lower end of section 42. It can beappreciated that this conduit will deflect the water being projectedfrom the tailpipe assembly downwardly and forwardly in order to producea thrust acting to move the boat rearwardly. The guide 45 acts toprevent the water from striking the transom of the boat and reducingthrust in this manner.

Because of the fact that the gate 30 is pivotal rather than slidable,frictional resistance to gate movement is greatly reduced. Any suitablematerial may be used in constructing the bearings 35 of the presentcontrol, for example, self-lubricating nylon or Teflon or possibly brassmay be used. From the above description, it can be appreciated that thepresent invention provides an improved means for controlling thedirection of a jet boat. It should be mentioned that the directioncontrol of the present invention can be operated while the engine 14 ofthe boat is operating at full speed and this is not possible withpresently available direction control devices. It can also beappreciated that the present invention provides a jet boat directioncontrol which lends itself to better styling as evidenced by theappearance of the housing 21. The simplicity of the mechanical couplingand the ease of operation of the present device should be obvious fromthe drawings and the above description.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionand the scope of the claims are also desired to be protected.

The invention claimed is:

1. A direction control system for watercraft comprising a conduitmounted on the craft and having an exit opening rearwardly thereof,means for pumping water through said conduit toward the exit thereof, agate mounted upon said craft for pivoting about a vertical axis, aportion of said gate having a generally arcuate shape and being locatedso as to move outside of the conduit and past the exit of said conduit,said arcuate portion being so proportioned that in one pivotal positionsaid gate does not affect flow from said exit and rearward projection ofsaid water is permitted, in a second position the water is bottled up insaid conduit, and in a third position the water is redirected in adirection forward of the craft.

2. A direction control system for watercraft comprising a conduitmounted on the craft and having an exit opening at the rear of the craftand near the bottom thereof, means for pumping water through saidconduit toward the exit thereof, a gate mounted on said craft forpivoting about a vertical axis, said gate having a portion formed in anarcuate shape, said conduit exit and gate portion being formed asadjacent part-cylindrical shapes concentric about said axis whereby saidgate can be pivoted through various positions and said arcuate portionremains in adjacency to said conduit exit during such pivoting, saidarcuate portion having spaced horizontally therealong a solid portionand a concave portion, said solid portion being pivotal to a positionwherein it blocks flow from said exit, and said concave portion beingpivotal to a position wherein it redirects flow from said exit in adirection forwardly of the craft, said concave portion being long enoughto form a vertical passage with the rear of the craft terminating in aforwardly facing outlet below the craft, said gate being pivotal to afurther position wherein said gate does not affect flow from said exit.

3. A direction control system for watercraft comprising a conduitmounted on the craft and having an exit opening at the rear of the craftand near the bottom thereof, means for pumping Water through saidconduit toward the exit thereof, a gate mounted on said craft forpivoting about a vertical axis, said conduit exit and gate being formedas adjacent part-cylindrical shapes concentric about said axis wherebysaid gate can be pivoted and said gate will remain in adjacency to saidconduit exit, said gate having an aperture therethrough of the same sizeand shape as the conduit exit, said aperture being so located that saidgate may be pivoted to a first position wherein said aperture is inregistry with said conduit exit, said gate having a concave portionformed therein, said gate being pivotal to a second position wherein theupper portion of said concave portion is in registry with the exit ofsaid conduit, said concave portion being long enough to form a verticalpassage with the rear of the craft, terminating in a forwardly facingoutlet below the craft, said gate being pivotal to a third positionwherein said gate blocks flow from said exit.

4. A direction control system for watercraft comprising a conduitmounted on the craft and having an exit opening rearwardly thereof,means for pumping water through said conduit toward the exit thereof, agate mounted upon said craft for pivoting about a vertical axis, aportion of said gate having a generally arcuate shape and being locatedso as to move outside of the conduit and past the exit of said conduit,said arcuate portion being so proportioned that in one pivotal positionsaid gate does not affect flow from said exit and rearward projection ofsaid water is permitted and in a further position the water isredirected in a direction forward of the craft.

References Cited in the file of this patent UNITED STATES PATENTS340,237 Nagel 6t al. Apr. 20, 1886 FOREIGN PATENTS 14,631 Great BritainJuly 15, 1905 OTHER REFERENCES New Zealand Patent Abstract No. 118,815,May 19, 1958.

4. A DIRECTION CONTROL SYSTEM FOR WATERCRAFT COMPRISING A CONDUIT MOUNTED ON THE CRAFT AND HAVING AN EXIT OPENING REARWARDLY THEREOF, MEANS FOR PUMPING WATER THROUGH SAID CONDUIT TOWARD THE EXIT THEREOF, A GATE MOUNTED UPON SAID CRAFT FOR PIVOTING ABOUT A VERTICAL AXIS, A PORTION OF SAID GATE HAVING A GENERALLY ARCUATE SHAPE AND BEING LOCATED SO AS TO MOVE OUTSIDE OF THE CONDUIT AND PAST THE EXIT OF SAID CONDUIT, SAID ARCUATE PORTION BEING SO PROPORTIONED THAT IN ONE PIVOTAL POSITION SAID GATE DOES NOT AFFECT FLOW FROM SAID EXIT AND REARWARD PROJECTION OF SAID WATER IS PERMITTED AND IN A FURTHER POSITION THE WATER IS REDIRECTED IN A DIRECTION FORWARD OF THE CRAFT. 